Draw tube removal

[marccongdon]

I've been trying to get the draw tube out of this actuator and it won't budge, I've been using a pipe wrench with rubber pads or a chain wrench with a rag and a pry bar between two of those bolts to hold it back. I'm hesitant to use any heat on it because I know there's an O-ring right behind there though I suppose at this point I should rebuild the cylinder anyway. From what I can find some drawings show the actuator with a lock nut on the outer side, some with no lock nut at all. The Actuator is an LMC ZKP150/52-22 and it's out of a 2001 Haas SL-20. I also can't get the back ring off, I've taken out the two set screws and given that some heat but still nothing. Is there something I'm missing here?

 

[wmpy]

I would put some heat on it. Since there is no locknut, it might just have some Loctite on there. You don't need much heat to melt Loctite.

Are you thinking that back ring is threaded on?

 

[marccongdon]

Yeah the back ring is threaded on, you can see about a thread and a half on the tube if you look at it from the other side. I got that one pretty hot but no luck there.

 

[bigjon61]

Whats up with the angled tapped holes directed towards the drawtube? Are they set screws on the draw tube?

 

[marccongdon]

Whats up with the angled tapped holes directed towards the drawtube? Are they set screws on the draw tube?

Yeah those are set screws but they don't go into the draw tube, That part is part of the cylinder. The draw tube threads into the piece on the front.

 

[guythatbrews]

Any luck with this? Maybe you can make a tool to get to a 1/2 drive on it and use an impact wrench. Not sure if you can damage what's inside the actuator with an impact wrench.

Once you do get it out it doesn't need to be bottomed out so hard. Use anti-seize. Once I started doing those two things I never had any more problems.

Sure hope nobody loctited it. That is a not ever good or necessary.

 

[Garwood]

Sure hope nobody loctited it. That is a not ever good or necessary.

Loctite is the only way to go if it doesn't have a locknut.

Chuck nut threads always get fucked up and the whole drawtube comes out with the chuck.

Loctite into the actuator and antiseize on the chuck nut threads is the way to go.

 

[guythatbrews]

Loctite is the only way to go if it doesn't have a locknut.

Chuck nut threads always get fucked up and the whole drawtube comes out with the chuck.

Loctite into the actuator and antiseize on the chuck nut threads is the way to go.

Different strokes. If it works for you it works.

I'll never loctite one and never have. 30 years no worries. And my advice is don't.

 

[Garwood]

Different strokes. If it works for you it works.

I'll never loctite one and never have. 30 years no worries. And my advice is don't.

You understand that most lathes not using a locknut on the drawtube are loctited at the factory right? Like the OP's setup is.

If you don't lock the drawtube in somehow then it doesn't have a fixed position and floats around. usually ends up to one end or the other. The end with less engagement stretches the threads and then you're really fucked. The chuck nut usually fills with swarf which fucks the threads. So the drawtube will come out with the chuck. This is real fun when your drawtube is longer than the space between the spindle face and tailstock.

Loctite is real easy to take apart. I use medium blue for drawtubes. It holds when I want it to and it comes apart with a heat gun. Real basic and easy. fear of Loctite seems very unfounded here.

 

[BobM3]

Tapping with a hammer on the face of the flange might loosen it.

 

[guythatbrews]

You understand that most lathes not using a locknut on the drawtube are loctited at the factory right? Like the OP's setup is.

If you don't lock the drawtube in somehow then it doesn't have a fixed position and floats around. usually ends up to one end or the other. The end with less engagement stretches the threads and then you're really fucked. The chuck nut usually fills with swarf which fucks the threads. So the drawtube will come out with the chuck. This is real fun when your drawtube is longer than the space between the spindle face and tailstock.

Loctite is real easy to take apart. I use medium blue for drawtubes. It holds when I want it to and it comes apart with a heat gun. Real basic and easy. fear of Loctite seems very unfounded here.

Never saw a lathe loctited ftom the factory. Not saying some don't do it, but all don't do it. I choose to go with no loctite.

If the drawtube is the correct length it cannot float around very much at all, if at all. The ones I've used are bottomed out in the nut at each. Screw it into the actuator until it bottoms. Screw the chuck nut on until it bottoms out. If they won't bottom out the drawtube is too short. If the drawtube is short enough to float that is another problem altogether and loctite is just a patch.

Again, this is the way the lathes I've worked with are set up. it is a good way. It's very possible other lathes are made differently.

 

[Garwood]

Never saw a lathe loctited ftom the factory. Not saying some don't do it, but all don't do it. I choose to go with no loctite.

If the drawtube is the correct length it cannot float around very much at all, if at all. The ones I've used are bottomed out in the nut at each. Screw it into the actuator until it bottoms. Screw the chuck nut on until it bottoms out. If they won't bottom out the drawtube is too short. If the drawtube is short enough to float that is another problem altogether and loctite is just a patch.

Again, this is the way the lathes I've worked with are set up. it is a good way. It's very possible other lathes are made differently.

Actuators typically have a lot more stroke than chucks do. This makes it real easy to think a drawtube is bottomed out in the actuator because there's shit in the threads because the drawtube came out when it shouldn't have and it's impossible to reach 3 ft down the spindle and clean those threads out so it gets run this way and everything works fine until the threads tear off the drawtube.

What is your aversion to Loctite? Loctite is a national treasure! It's basically antiseize that only comes apart when you want it to. Loctite protects the threads- Keeps shit out so the threads stay nice and do their job.

 

[guythatbrews]

You talked me into it! Loctite from now on.

 

[Garwood]

You talked me into it! Loctite from now on.

No I didn't. I want more of a fight than that. You can't just give up and pretend I'm right like that.

This is bullshit. You need to hold your position and transition into political insults somehow. That's how this internet thing works.

 

[guythatbrews]

No I didn't. I want more of a fight than that. You can't just give up and pretend I'm right like that.

This is bullshit. You need to hold your position and transition into political insults somehow. That's how this internet thing works.

Good one! That really made me laugh.

I guess I could say why not use loctite on everything whether you need it or not. Just store a heat gun or torch with your wrenches. Easy! And also I could say if you are using loctite because you screwed a bunch of crap into the actuator threads maybe you should thunk a little harder on that one.

Buy I won't say those things!

 

[marccongdon]

Well I did end up getting it all apart yesterday, Ended up requiring some pretty hefty hits with a hammer on the chain wrench. The draw tube wasn't corroded or loctited. It looks like there was chip build up into the threads from the back side that made it difficult to break loose but once it broke loose it spun out by hand. The back ring was loctited on however. I've got some new seals coming from a local hydraulics shop so hopefully I can avoid the 400 dollars that haas/lmc wants for the seal kit.

 

[guythatbrews]

Chips in there is a bad thing! I take great pains to clean out the drawtube when removing it or putting in a spindle liner.

Make a nozzle that fits into the airline quick coupler to clean out the drawtube. It's made from a 3/8 female npt quick coupler with a cored brass hex plug screwed in. The plug has six angled nozzle holes drilled into the flats, angled so they point forward, away from the air hose. Snake it through the drawtube several times to blow all the crap out. Then run a rag ball taped to a rod through to swab out any oily, flaky crap.

An ounce of prevention...